Researchers from the University of Chicago, the University of Missouri and the U.S. Department of Energy’s Argonne National Laboratory have developed by method which allows flat nanoparticle sheets to curl into a tube-like on passing an electron beam through it.

Gold nanoparticles are connected by a series of oil-like organic molecules, forming sheets when they’re floated on top of water. The water is then evaporated away, leaving small sticker-like patches over holes in a frame below. Organic molecules mentioned are hydrophobic, so they’re not evenly distributed top-to-bottom across the sheet after the evaporation.

When an electron beam hits the surface, it causes the molecules to create a new bond with their nearest neighbors, but because of their distribution more occur on one side than the other. In turn, there’s an unsymmetrical stress in the sheet that causes it to curl or fold.

This unsymmetrical stress in the sheet has not been controlled by scientists yet, so they don’t really have a say on how the sheet folds. But once they get a handle on this, this technique can be employed on almost any nanoparticle membrane.

Author:Technology Blog